The secrets to this celestial buttercream, writes Vancouver baker Rosie Daykin in her first book, Butter Baked Goods (Random House, 2013), are "making sure your butter is not too cold, and then whipping it like crazy!" When properly whipped, buttercream is supremely fluffy--almost like whipped cream--and surprisingly un-greasy. "When it's right, it's a breeze to use," adds Daykin. "It's like pushing air around." Also, because her version has a lot less sugar than most buttercreams, it won't set your teeth on edge.